"Amicon Ultra concentrator filter is really fast and amazing. As they have, even for smaller volumes, reduced the loss of protein in the sample just by sticking it on to its wall. Also they are designed in such a way that it’s very easy to use. It looks like an Eppendorf tube! I will recommend this for others for using it."

"Amicon® Ultra-0.5 Centrifugal Filter Units are useful for protein purification and concentration. This filter device can remove proteins bellow 3 kDa. This filter device can be used to concentrate a pure protein with a molecular mass above 3 kDa. The recommended velocity to spin this device is 5000-7000 RPM, however when the filter is used for long time it may be useful to decrease this speed up to 3000 RPM as there is Always chance of loss of proteins after using it for a long time. The second more important thing is to fill this device up to a maximum of 0.5 ml as there is a chance of filter loss above this volume. It is suitable for small scale protein concentration and purification. I recommend it to use for protein separation and concentration and to store this device either in 20% Ethanol or 0.02% Na-azide solution after use."